Pump



June 26, 1956 w. A. sHERwooD 2,751,849

PUMP

Filed Nov. l, 1954 ATTORNEYS United States Patent O ice PUMP Walter A. Sherwood, Hempstead, N. Y., assignor to The Farmingdale Corporation, Farmingdale, N. Y., a 'corporation of New York Application November 1, 1954, Serial No. 466,095

Thisinvention relates to a pump for fluids of appre- .ciable viscosity and particularly to such a pump in which the shear resistance of the uid is utilized as a causational factor in creating a pressure condition.

An object ofthe invention is to provide such a pump in which centrifugal force is utilized in combination with (the shear resistance to give improved results.

.line II--Il of Fig. 1, looking in the direction of the =ar rows, and

Fig. 3 represents a transverse section, taken onthe line lll-lll of Fig. l looking in the direction of the arrows. i

Referring to the drawings, the pump stator comprises an essentially cylindrical body portion 1, the interior of which is in the form of a more or less elongated cylindrical chamber 2. At one end said chamber terminates in the axially bored wall 3, and at the other end the body portion is enlarged to form the annular flange 4, internally threaded at 5. A bushing 6 is screwed into said enlarged end, the inner end of the bushing being designed to seat tightly against the annular shoulder 7 around the end of the chamber 2, while the enlarged head 8 of the bushing compresses a sealing ring 9 in the space between said head and the outer end of the ange 4. A iluid inlet pipe 1G is screwed tightly into the interior of the bushing 6.

The pump rotor comprises an elongated cylindrical body 11 having a length such that it will fit in the chamber 2 with free tit clearance at each end. Throughout the greater part of its length said body has a diameter slightly less than the interior diameter of the chamber so that there exists also a slight clearance between the concentric cylindrical surfaces of the rotor and stator. The rotor body is mounted at one end on a drive shaft 12, journaled in the axial bore of the wall 3, said shaft engaging the rotor body, for instance, with a driving tit between the end of the shaft and a hole in the end of the rotor, not shown. The shaft is driven in any suitable manner, as by means of a motor M.

From its free end the rotor body is axially bored as shown at 13 throughout most of its length and at one or more points in the middle half of the body, longitudinally considered, said bore communicates with the surface of the rotor body through radial passages 14. In the example illustrated there are three such passages in line along one side of the rotor with their continuations across the complete diameter thereof constituting three Patented June 26, 1956 :2 more ,passages 14 angulaily spaced 180 'from the passages 14.A In the zone of Veach said 'line of passages the surface of the rotor is slightly relieved, V`as.indicated,at 15, 15 in order to increase the clearance in such zones.l

Adjacent each line kof passages the rotor surface is provided with longitudinal grooves 1'6, 16' extending Afrom points near the freefendpo'f the rotor body to .points near the drive-shaft end. At the latter .points 'the rotor surface is .provided with `a circumferential groove 17. Vanes or blades 18, 18 preferably of suitable antifriction material, tit freely inthe grooves 16, v115 with vtheir outer surfaces bearing against the inner cylindrical wall of the chamber 2. The edges 'of .the grooves 16, 16 on the sides opposite to the passages V14, 14 are preferably beveled to form elongated pressure zones' 19, 19 which open at one end into lthe 'circumferential groove 17.

In the wall of the chamber 2 and registering with the groove 17 there is formed the outlet passage 20, into which may be screwed suitable .fittings 21'for connection Vof the pressure yside of the'pump 'to any desired utilization apparatus, not shown.

At the drive-shaft Aend of the rotor one or more small bleed passages 22 may be 4drilled from the end surface of the rotor to the 'end ofthe .bore 13. Leakage of uid through the drive shaft journal may beprevented vorminimized, if desired, Vbythe provisionof va suitable Vshaft seal 23 'in ther'ecess 24 at Vthe end of the stator body 1.

VIn operation, the rotor 11 Ais driven `by lthe motor M in the direction 'indicated by kthe arrows. The duid to be pumped is supplied through the pipe 10, vfrom lwhich it ows into the bore`-13 of .the -rotor and thence vinto the radial passages 14, -14-. Flow through said lpassages :is materially aided by centrifugal torce resulting from rotation of the rotor, so that Awhen the fluid enters the zones 15, A15' it is 'already under somewhat increased pressure. From the zones 15V, `15"-the -iluid Yilows, particularly in Va circumferential direction, through the clearance between the rotor and the stator, but this flow is interrupted by the vanes 13, 1S against which the iluid builds up pressures (in the zones 19, 19') which can be very high. Since the zones 19, 19 are in communication with the groove 17, the uid under pressure will lill said groove and feed thence through the outlet 20 to the point of use.

The pressure in zones 19, 19' is due in substantial part to the shear resistance in the duid lilling the small clearance between the relatively moving surfaces of the rotor and stator. This shear and uid wedge eiect can be varied by controlling or predetermining the affinity between the uid and either or both suaces; for increased pressure the fluid should tend to adhere to the stator and be repelled by the rotor. The vanes 18, 1S are caused to press outward against the cylindrical surface of the stator by centrifugal force; the centrifugal pressure of the vanes thus varies in the same sense as the uid pressure in the pressure zones.

It is evident that the uid under pressure in the zones 19, 19 and groove 17 will tend, if possible, to leak endwise, toward the ends of the rotor. Such leakage is opposed inherently by the resistance to ow resulting from the length of the land areas beyond the ends of the pressure zones, and this resistance can be increased by reducing the clearance in said areas, i. e., the diameter of the rotor adjacent its ends can be made greater than the diameter between said end areas. The clearances will normally be so slight that illustration of the clearance difference is impossible except with considerable exaggeration, and the drawing is to be so understood. Any uid leakage at the free end of the rotor returns the duid to the inlet (low pressure) side where it can flow again into the bore 13. Leakage at the driveshaft end of the rotor is also led directly to the low pressure intake `circumferentially around the rotor. abutment is provided, kthe pump can operate but the unment in which the bore 13, passages 14, 14', zones 15,

15', grooves 16, 16 'and 17, and zones 19, 19 are formed. The drilling and/ or lmachining of such configurations in the solid cylindrical rotor body. is quite simple.

In the pump shown and described the rotor is provided with two'abutments (varies) with their associated elements, located at diametrically opposite points. lt will be understood, however, thatthe structure and operation would be basically theV same if three or more abutments Were provided, so long as they are uniformly spaced If only one such balanced condition of the rotor must then be taken into account in some suitable manner, e. g., operate only at low speeds, or correct the balance;Y Y

It will be evident that various changes can be made in the form, construction and arrangement of the several parts without departing from the spirit and scope of the invention, hence I do not intend to be limited to the Yparticular embodiment shown and described.

Vsiliently against the surface of said chamber along at least a major part Vof the length thereof, an axial bore in said rotor, at least one radial passage providing communication from said axial bore to the surface of the rotor at a pointY adjacent to said vane on the upstream side thereof considered circumferentiallyV with respect to the direction of rotation of the rotor, means for supplying uid to said axial bore and means for conducting fluid under pressure from the clearance on the downstream side of said vane and for delivering said uid.

2. A pump according to claim l in which the means for conducting tiuid includes an annular groove in the surface of the rotor, and in which there is an outlet passage in the stator so located as to be in continuous communication with said groove. y Y

3. A pump according to claim l in which there are a plurality of radially iioating elongated axially disposed vanes, spaced uniformly in the circumferential direction.

4. A pump according to claim 1 in which the clearance between the rotor and the stator is reduced in zones adjacent the ends thereof.

5. A pump according to claim 1 in which the surface of the rotor is relieved to provide'a fluid distributing inlet zone extending axially and communicating with said radial passage.

6. A pump according to claim 1 in which the rotor is provided with at least one axially disposed groove having radial depth to receive and guide' said vane.

7. A pump according to claim 6 in which the edge of said axially disposed grooveron the downstream side of the vane is cut away to provide a iiuid pressure zone.

8. A pump according to claim 7 in which the means for conducting fluid includes an annular groove in the surface of the rotor and in which saidaxially disposed groove is in communication with said annular groove.

9. A pump according to claim l in which the axial bore in the rotor extends -inward from-one end of said rotor and in which the meansfor rotating .the rotor include a drive shaft connected to the other end of said rotor and journaled in an end wall of the stator. y Y

10. A pump according to claim 9 in which the drive shaft end of the rotor is provided with at least one pas-A sage-extending from the end surface of the rotor to the axial bore therein.

No references cited. 

